Azo dye and process of making same.



UNITED STATES Patented May 19, 1903.

EMILE A. FOURNEAUX, OF NEW YORK, N. Y., ASSIGNOR TO HERMAN-A.

' METZ, OF BROOKLYN, NEW YORK.

AZO DYE AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent N 0. 728,455, dated May 19,1903. Application filed October 28, 1902. Serial No. 129,088. (Nospecimens.)

To all whom it may concern:

Be it known that I, EMILE A. FOURNEAUX, a citizen of the United States,residing in New York, borough of Manhattan, and State of New York, haveinvented certain new and useful Improvements in Azo Dyes and Processesof Making the Same, of which thev following is a specification.

In the application heretofore filed by me on September 16., 1902, SerialNo. 123,558, for improvements in azo dyes and processes of making thesame I have shown that the azos derived from diazotized nitroaminocompounds and beta-naphthol, which being insoluble are not suitable forthe manufacture of lake and pigment colors, as such in the finishedstate can be made available for this purpose by combining the nitrodiazocompound with beta-naphthol in the presence of a diazo compound derivedfrom an aminosulfonic acid or by the action of a nitrodiazo compound onan azo dye derived from a diazosulfonic acid and beta-naphthol. I havesince found that similar and even more valuable substances, whichconsist in the main of the azo dyes derived from nitrodiazo compoundsand beta naphthol in such an extremely fine state of division that theywill react readily with metallic salts, forming lakes, can also beobtained by coupling the nitrodiazo compound witha mixture ofbeta-naphthol and other phenolic bodies, especially the sulringconstantly, the amount of alkali being such that the reaction of theliquid is slightly alkaline after coupling. It is also desirable to usethe diazo compound in such a proportion that it will just saturate thetotal of the phenolic bodies. In other words, for one molecularproportion of the diazo compound it is best to use such quantities ofbeta-naphthol and the other phenolic body that they sum up to onemolecular proportion. Supposing, for

instance, that one molecular proportion of paranitrodiazobenzol andbeta-naphthol and beta-naphtholmonosulfonic acid F be used in theproportion of three parts of the former to one part of the latter, itwould be advisable to use three-fourths of a molecular proportion ofbeta-naphthol and one-fourth of a molecular proportion ofbeta-naphtholsulfonic acid F and a sufficient amount of alkali to insurea neutral or slightly-alkaline reaction of the liquor after thecombination has taken place.

In the ordinary process of manufacturing lakes from diazotizedparanitranilin and betanaphthol, which consists in mixing a suitablebase with the proper amount of an alkaline beta-naphthol solution andthen allowing the corresponding amount of a diazotized paranitranilinsolution to run into this mixture, thus forming the insolubleazocompound in the presence of the base and precipitating it on thebase, it has occasionally been customary to add small quantities of suchphenolic bodies as mentioned in this ap-' plication to the bet-anaphtholsolution in order to obtain bluer shades; but the amounts added werelimited to a very small proportion, usually not exceeding five per cent.of

the amount of naphthol used, as the color became partly soluble in waterif more was used, which is not desirable in that process. I wish toemphasize that this method has nothing in common with my process but thematerials used, nor is the proportion of these materials the essentialdifference, as the nov elty of my process consists intheentirely-unexpected and newly-observed fact that by the addition ofsuch phenolic bodies in sufficient quantities to the alkalinebeta-naphthol solution before coupling with the nitrodiazo body theinsoluble azo body resulting from the action of the nitrodiazo body onbeta-naphthol is precipitated in an entirely new form of such extremedivision that it reacts readily with metallic salts, forming thusinsoluble lakes and being available for the manufacture of lakes by thesame. general methods as the sol-uble azo dyes commonly used for thispurpose. This constitutes an essential progress. Whether the soluble azocolors incidentally formed by the action of the nitro- PATENT Orr ga/nICO tation when the resulting dye is used for the u manufacture of lakesis immaterial. They are merely unavoidable by-products. hen it isdesired to vary the shade of the resulting body, it is feasible to addother diazo compounds to the nitrodiazo compound mainly used; but thetotal amount of diazo compounds used should be just sufficient toneutralize the total amount of phenols used, as thus the best resultsare obtained. After the coupling is completed it is usually preferableto add a certain amount of common salt, which facilitates filtering, andto wash the filtered product with a diluted salt solution. The productis then reduced to paste form, in which form it is applied for themanufacture of lakes.

Example 1. One hundred and thirty-eight parts paranitranilin are dividedin one thousand parts water containing seventy two parts of commercialsodium nitrite and the temperature is lowered nearly to thefreezingpoint by the addition of ice, when three hundred and sixty partshydrochloric acid of 20 Baum are added. The diazo solution thus obtainedis filtered and diluted to ten thousand parts at a temperature notexceeding 15 centigrade. One hundred and fifteen parts beta-naphthol aredissolved in the calculated amount of caustic soda and the necessaryamount of water. To this solution is added a solution of forty-nineparts of the sodium salt of the naphtholsulfonic acid 2.7 and twohundred and seventy-five parts of calcined sodium carbonate, and thewhole diluted to ten thousand parts, maintaining the temperature at notover 15 centigrade. The diazo solution is then allowed to run slowlyinto the naphthol solution under continuous stirring. The solution isthen allowed to stand for several hours, after which salt is added, thesolution filtered, and the precipitate washed with a diluted saltsolution. The dye is then made into a pulp.

Example 2. A diazo solution is prepared from one hundred andthirty-eight parts paranitranilin, as above. On the other hand, twohundred and twenty parts of paranitranilinorthosulfonic acid aredissolved in boiling water and the solution cooled finally by additionof ice nearly to the freezing-point, and one hundred and seventy partsof hydrochloric acid of 20 Baum are added and the body diazotized byadding a solution of seventytwo parts of commercial sodium nitrite and.enough water to prevent the diazo body from separating in crystallineform. Two hundred and thirty parts of beta-naphthol are dissolved in thecalculated quantity of caustic soda and the necessary quantity of water,and a solution of eighty parts betaoxynaphtoic acid dissolved in thecalculated amount of caustic soda, and four hundred and twentyfour partsof calcined sodium carbonate are ing 15 centigrade.

added, the whole being made up to twenty thousand parts at a temperaturenot exceed- The above diazo solutions are then mixed and the mixture runslowly, while stirring constantly, into the above naphthol solution,then salted, filtered, and washed as in Example 1.

The azo dyes thus obtained can be used in the manufacture of red lakeand pigment colors, being essentially composed ofparanitrobenzolazobeta-naphthol or a mixture of this body with otherbeta naphthol-azo compounds, which forms a gelatinous paste that isinsoluble in water, but so finely divided as to react readily withmetallic salts and produce red lakes having a bluish undertone with agreat fastness to light.

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. The process herein described of making an azo dyesuitable for the manufacture of red lake and pigment colors, whichconsists in coupling a nitrodiazo compound with a mixture ofbeta-naphthol and other phenolic compounds as herein specified in suchproportions that the resulting insoluble azo compound is formed in suchan extremely finely divided condition as to be suitable as such for themanufacture of lake and pigment colors, substantially as set forth.

2. The process herein described of making an azo dye suitable for themanufacture of red lake and pigment colors, which consists in combininga nitrodiazo body and another diazo body with a mixture of beta-naphtholand other phenolic compounds as herein specified in such proportionsthat the resulting insoluble azo compound is formed in such an extremelydivided condition as to be suitable for the manufacture of lake and pigment colors, substantially as set forth.

3. An azo dye suitable for the manufacture of red lake and pigmentcolors, obtained by combining diazotized paranitranilin with a mixtureof beta-naphthol and other phenolic bodies, and consisting essentiallyof paranitrobenzolazobeta-naphthol, or a mixture of this body with otherbeta-naphtholazo compounds, forming a gelatinous paste which isinsoluble in water and so finely divided as to react readily withmetallic salts and produce red lakes with a bluish undertone having agreat fastness to light, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

EMILE A. FOURNEAUX.

Witnesses:

PAUL GoEPEL, HENRY J. SUHRBIER.

